Vehicle body closure

ABSTRACT

A vehicle body closure includes a base having fore and aft pins to mate with holes in a vehicle body to locate the base in an opening in the vehicle body, a releasable top lock to secure the base to the body, and right and left flipper panels pivotally mounted thereto, with each flipper panel movable between a raised position opening half of the opening and a lowered closed position covering half the opening. A door-controlled bodymounted sequentially operating hydraulic linear actuator includes a spring-biased movable cylinder operably connected to a locking mechanism and a movable piston operably removably connected to a base-mounted raising mechanism through the aft pins to sequentially operate in one direction to unlock and then in the opposite direction to raise a flipper panel in response to differential fluid pressure and to operate in the one direction to lower the flipper panel and then in the opposite direction to lock it in response to opposite differential fluid pressure. The base and the flipper panels may also be removed giving a completely open body.

States Pa-tet 72] Inventors Robert A. Vogelei Lathrup Village; RichardW. Klrkman, Harpenden, England; Alverson B. Williams, Warren, Mich. [211App]. No. 860,907 [22] Filed Sept. 25, 1969 [45] Patented Nov. 23, 1971[73] Assignee General Motors Corporation Detroit, Mich.

[541 VEHICLE BODY CLOSURE 8 Claims, 9 Drawing Figs.

[52] US. Cl 296/146, 49/280, 42/340; 292/144 [51] Int. Cl B60j 5/04 [50]Field of Search 296/146, 137,28 K; 49/280, 340; 292/144, 33, D16. 65

[56] References Cited UNITED STATES PATENTS 2,507,822 5/1950 Sherrill292/DlG. 65 2,809,682 10/1957 Daniels.... 296/146 X 2,938,749 5/1960Podolan 296/28 X 3,348,877 10/1967 Caramanna 296/137 FOREIGN PATENTS v5/1955 Great Britain Primary Examiner- Benjamin Hersh AssistantExaminer-John A. Pekar A!!0rneys-W. E. Finken and Herbert FurmanABSTRACT: A vehicle body closure includes a base having fore and aftpins to mate with holes in a vehicle body to locate the base in anopening in the vehicle body, a releasable top lock to secure the base tothe body, and right and left flipper panels pivotally mounted thereto,with each flipper panel movable between a raised position opening halfofthe opening and a lowered closed position covering half the opening. Adoor-controlled body-mounted sequentially operating hydraulic linearactuator includes a spring-biased movable cylinder operably connected toa locking mechanism and a movable piston operably removably connected toa base-mounted raising mechanism through the aft pins to sequentiallyoperate in one direction to unlock and then in the opposite direction toraise a flipper panel in response to differential fluid pressure and tooperate in the one direction to lower the flipper panel and then in theopposite direction to lock it in response to opposite differential fluidpressure. The base and the flipper panels may also be removed giving acompletely open body.

VEHICLE BODY CLOSURE This invention relates to removable closures forvehicle body openings and more particularly to a closure which may beremoved and installed as a unit and which includes flipper panels, eachselectively operable by a linear actuator to open and close a portion ofthe opening when the closure is in stalled.

In a closed body low-profile vehicle, entry and exit may be difficultdue to the low roof. While entry and exit may be easier in a completelyopen-body low-profile vehicle because of the absence of the roof, suchvehicles need a roof during times of adverse weather conditions.

The closure of this invention permits the passengers to select either acompletely open-body low-profile vehicle or a closed-body low-profilevehicle which includes a closure responsive to door movement toautomatically partially open and facilitate passenger entry or exit. Inthe preferred embodiment, the closure removably covers an opening in theroof of an open-body vehicle and includes a base pivotally mountingright and left flipper panels each of which is movable independently ofthe other between an open position, opening half of the roof opening,and a closed and locked position, closing half of the roof opening. Thebase removably mounts the closure to the body in the opening and alsoreleasably operably connects a body-mounted door-controlled actuator toeach flipper panel to move the panels between the two positions. Theactuator includes a biased movable cylinder and a movable piston drivenby a reversible fluid pump whose direction of operation is controlled byvehicle door position. Each actuator sequentially moves a respectivepanel in response to differential fluid pressure to either unlock andraise the flipper panel to the open position or in response to oppositedifferential fluid pressure lower the flipper panel to the closedposition and lock it. The closure may also be removed to give acompletely open body.

Therefore the primary object of this invention is to provide a closurewhich may be removed and installed as a unit and which includes flipperpanels selectively operable to open and close a portion of the roof whenthe closure is installed. It is another object of this invention toprovide such a removable closure wherein each flipper panel issequentially unlocked and raised to an open position or lowered to aclosed position and locked by the sequential operation of a doorcontrolled fluid actuator. It is a further object of this invention toprovide a linear actuator adapted to be mounted to a vehicle body andreleasably operably connected to a pivotal flipper panel for moving theflipper panel sequentially between raised-open and lowered-closed andlocked positions. It is another object to provide such an actuatorincluding a movable cylinder, biased in one direction. and a movablepiston to automatically sequentially operate in one direction and thenin the other in response to opposite differential fluid pressure. It isyet another object of this invention to provide a removable closure withlinear actuator driven movable flipper panels which are automaticallydisconnected from respective body mounted sequential linear actuatorsupon removal of the closure and which are automatically connected to theactuators upon remounting the closure.

These and other objects of this invention will become apparent from thefollowing detailed description and drawings in which:

FIG. I is a perspective view of a portion ofa vehicle body having anopening in the roof thereof, covered by a removable closure includingmovable flipper panels, according to this invention, with the rightpanel shown in a closed and locked position and the left panel shown inan unlocked and open position and with the operating system for theflipper panels shown in phantom lines.

FIG. 2 is a fragmented perspective view of the operating mechanisms ofthe closure with part of the closure and the rear roof section of thevehicle shown in phantom lines.

FIG. 3 is a view similar to FIG. I showing the removable closure mountedto the vehicle in solid lines and removed from the vehicle. with bothflipper panels in open position, in phantom lines.

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 3.

FIG. 5 is a sectional schematic view of the linear actuator foroperating a flipper panel taken along the line 55 of FIG. 2 showing thelinear actuator when the flipper panel is in the closed and lockedposition.

FIG. 6 is a view similar to FIG. 5 showing the linear actuator when theflipper panel is in the closed and unlocked position.

FIG. 7 is a view similar to FIG. 5 showing the linear actuator when theflipper panel is in the unlocked and open position.

FIG. 8 is a view similar to FIG. 5 showing the linear actuator when theflipper panel is in the closed and unlocked position.

FIG. 9 is a schematic of the actuator, fluid pump, and electrical systemused to control the operation of a fluid pump supplying fluid to thelinear actuator.

Referring now to F [OS 1 and 3, a vehicle body 10 has a roof 12 with anopening 14 therein bounded at the front by windshield header 16, at eachside by a side window 18 mounted in conventionally opening and closingdoors 20, and at the rear by a forward wall 22 of the rear roof section24. As shown in FIG. 3, the windshield header 16 has a pair of spacedvertical round tapered holes 26 equidistant from the center line of thevehicle body 10, and as shown in FIG. 2, the forward wall 22 has a pairof spaced horizontal square tapered holes 28 equidistant from thecenterline of the vehicle body 10.

Referring particularly to FIG. 3, the opening 14 is covered by aremovable closure 30 called a flipper panel roof section which includesa base 32 for mounting transverse the opening 14 between the windshieldheader I6 and the forward wall 22 along the centerline of the vehiclebody 10 and also includes right and left flipper panels 34 pivotallymounted to the base 32 as will later be described. The base 32 and theflipper panels 34 together in the closed position cover the opening 14and conventionally sealingly engage the windshield header 16, thewindows 18 and the forward wall 22 of the rear roof section 24 to sealthe interior of the vehicle body 10. As shown, the right and leftflipper panels 34 are identical except for being mirror images of eachother and as such only one flipper panel will be described in detail.The flipper panel roof section is shown with two flipper panels but itcould have any number including only one.

As seen in FIG. 3, base 32 has at its front edge a pair of spaceddownwardly extending round tapered pins 36 equidistant from the base 32centerline and, as seen in FIG. 2, the base 32 has at its rear edge apair of spaced rearwardly extending square tapered pins 38 equidistantfrom the base 32 centerline. The tapered pins 36 and 38 mate with thetapered holes 26 and 28 respectively to locate the base 32 centerline onthe vehicle body 10 centerline and attach the base 32 to the body 10. Onthe front underside of the base 32 is mounted a conventional convertibletop latch 40 for securing the base 32 to the vehicle body 10 by engagingthe underside of the windshield header 16 after the base 32 has beenpositioned by the pins 36 and 38.

The closure 30 is manually mounted to the body 10 over the opening 14 byinitially positioning the closure 30 above the opening 14 and slightlyforward of its final position with the centerline of the base 32 on thecenterline of the vehicle body 10 to line up the pins 36 and 38 with theholes 26 and 28. The rear edge of the base 32 is lowered slightly,starting the square tapered pins 38 into the square tapered holes 28 andthe base 32 is moved rearwardly. When the base 32 is directly over theopening 14, the front edge is lowered. sliding pins 36 into taperedholes 26 to laterally locate the closure 30. The top latch 40 is thenmanually locked, securing the base 32 to the windshield header 16 tocomplete the mounting of the closure 30 to the vehicle body 10 over theopening 14.

To remove the closure 30 once both of the flipper panels 34 have beenunlocked and raised as will be later explained, the top latch 40 ismanually unlocked and the front edge of the base 32 is raised to movepins 36 from holes 26. The base 32 is then slid forward to slide thepins 38 from holes 28. The closure 30 is then completely free of thevehicle body 10 and the vehicle body 10 has an open top.

The square tapered pins 38, besides locating the rear of the base 32,also drivingly connect the closure 30 to the drive mechanism mounted inthe rear roof section 24. The drive mechanism is the same for each panel34 so that only one will be described. As seen in FIG. 2, pin 38 has acylindrical portion, forward of the square tapered portion. which isrotatably mounted in aligned holes through the walls of a channelbracket 42 mounted within the base 32 adjacent the rear edge thereof.The forward end of pin 38 fixedly mounts a sector gear 44 so thatrotation of pin 38 rotates the sector gear 44.

Mounted in the base 32 adjacent the channel bracket 42 is anotherchannel bracket 46 with both ends thereof having the webbing relieved.Each end of bracket 42 has an aligned pair of holes through the wallsthereof. Between the walls of the channel bracket 46 at each end thereofis positioned the looped end of a hinge strap 48. A pin 50 having asector gear 52 on the aft end thereof is passed through the rear hole ofthe aligned holes, through a looped end of the strap 48 and through theforward hole of the aligned holes to pivotally mount the strap 48 to thebase 32. The pin 50 is so positioned that the teeth of the sector gear52 mesh with the teeth of the sector gear 44 for a drivinginterconnection therebetween. The strap 48 is nonrotatably attached tothe pin 50 by any conventional method such as by pins.

The hinge strap 48 is attached to the rear inboard portion of theflipper panel 34 by conventional means such as bolts to drivinglypivotally attach the flipper panel 34 to the base 32. The front inboardportion of the flipper panel 34 is pivotally mounted to the base portion32 by a conventional strap hinge 54. The flipper panel 34 pivots onhinges 54 and 48 to move, in response to rotation of the square taperedpin 38, between a closed position, shown in FIG. I by the right panel,covering the opening 14. and an open position, shown in FIG. 1 by theleft panel opening the opening 14. The hinges 54 and 48 in the openposition of the panel 34 engage the base 32 to prevent further openingmovement.

As was previously described, the square tapered pin 38 mates with thesquare tapered hole 28 in the roof rear section 24 to provide forlateral location of the base 32. However, this mating does more thanlocate the base 32 as it also provides a driving connection between thebase 32 and the mechanism in the vehicle body for raising and loweringthe roof flipper panel 34.

As seen in FIG. 2, the square tapered hole 28 is in the forward end of ashaft 56. A pair of shafts 56, are both rotatably mounted in suitablespaced relationship by housing 58 in the rear roof section 24. The rearend of shaft 56 has a crank 60 nonrotatably attached thereto. The crankhas an opening 62 in its upper end through which is inserted and securedby a cotter pin to the hooked end of a piston rod 64. The piston rod 64is moved back and forth by linear actuator 66 which will be laterdescribed. As the piston rod 64 reciprocates, the crank 60 rotates shaft56 in the housing 58 to drive the flipper panel 34 between a raised-openposition and a lowered-closed position.

As shown in FIG. 2, the flipper panel 34 contains, adjacent its outboardedge, part of a locking mechanism 68 for releasably securing theoutboard edge of the panel 34 to the vehicle body 10. The lockingmechanism 68 releasably secures the forward wall of the flipper panel 34to the windshield header 16 and the rearward wall of the flipper panel34 to the forward wall 22 of the rear roof section 24. The flipper panelmounted part of the locking mechanism includes a rod 70 with a bolt 72on the fore end thereof. The rod 70 is slidably mounted to the flipperpanel 34 for fore-and-aft movement by an apertured forward angle bracket74 and a rear bracket 76 with a cylindrical opening 78. The brackets 74and 76 are so positioned on the flipper panel 34 that when the flipperpanel 34 is closed, the bolt 72 will extend under the windshield header16 as the rod 70 is moved forward to lock the flipper panel 34 thereto.The bracket 74 is also so positioned adjacent the front and outboardwalls of the flipper panel 34 that the bolt 72 engages the bracket 74 tolimit rearward movement of the rod 70 just as the bolt 72 has ceased toprotrude beyond the forward wall of the flipper panel 34. The rearbracket 76 mounts on the rear wall of the flipper panel 34 adjacent theoutboard end thereof and is of sufficient length to enable the rod 70 toslide fore and aft without the rear end thereof dropping out of theopening 78. The rod 70 and bolt 72 in the rear or unlocked position areflush with the forward and rearward walls of the flipper panel 34.

The rod 70 is biased rearwardly to the unlocked position by a coilspring 80 therearound with the fore end of the spring seating againstangle bracket 74 and the aft end thereof seating against a pin 84through a hole in the rod 70.

The locking mechanism 68 is completed by the part thereof mounted in therear roof section 24. Brackets 86 are mounted to the forward wall 22adjacent the position of each of the rear brackets 76 on the flipperpanel 34 in closed position. The bracket 86 contains a tubular hole 88aligned with the cylindrical opening 78 of the rear bracket 76 in theclosed position of the flipper panel 34 for slidably receiving andsupporting a locking pin 90. The locking pin 90 is tapered on its foreend and is pivotally attached through its apertured rear end by a pin 92to one leg of a bellcrank lever 94 pivoted at 96 to the rear roofsection 24. The other leg of lever 94 is connected to an apertured endof link 98 by pin 100. The apertured other end of link 98 is connectedto the apertured outboard end of a cylinder rod 102 of the linearactuator 66 by a pin 104.

As the cylinder rod 102 is moved back and forth, as will later bedescribed, the link 98 pivots the bellcrank lever 94 to move the lockingpin 90 between an unlocked position wherein the locking pin 90 is flushwith the forward wall 22 of the rear roof section 24 and a lockedposition wherein the locking pin 90 protrudes forwardly from the forwardwall 22 of the rear roof section 24.

The locking of the closed flipper panel 34 occurs by the locking pin 90sliding forward from the tubular hole 88 of the bracket 86 into thecylindrical opening 78 in the bracket 76 aligned therewith to secure therear edge of the flipper panel 34 to the rear roof section 24. As thelocking pin 90 slides forward, it engages the rear end of the rod 70 todrive rod 70 forward and slide bolt 72 under the windshield header 16 tosecure the forward edge of the flipper panel 34.

Unlocking of the closed flipper panel 34 occurs by the locking pin 90sliding rearward to the unlocked position in the tubular hole 88 in thebracket 86, flush with the forward wall 22 to free the rear edge offlipper panel 34. The spring 80 simultaneously drives the rod 70rearwardly to the unlocked position wherein the bolt 72 no longerengages the windshield header l6, freeing the forward edge of theflipper panel 34 from the vehicle body 10.

The flipper panel 34 has an open and closed position and while in theclosed position is either locked or unlocked from the vehicle body 10.The two terminal positions of the panel 34 are open or closed andlocked. In moving between these terminal positions, the proper sequencymust be followed. From the closed and locked position, the flipper panel34 must be unlocked and then raised to the open position where thehinges 48 and 54 engage the base 32. From the open position, the flipperpanel 34 must be lowered to the closed position, where it engages thewindshield header [6, and then locked. The proper sequence of operationsfor each flipper panel 34 must come from its respective linear actuator66.

The linear actuator 66 for each flipper panel 34, shown in FIG. 2 andschematically illustrated in FIGS. 5, 6, 7, and 8, includes a box-shapedhousing conventionally secured laterally of the vehicle body 10 withinthe rear roof section 24. The box-shaped housing 110 has both sides andthe top cut out to provide access to the interior thereof. Thebox-shaped housing 110 has an opening 112 in the inboard end, or rightend in FIGS. 5-8, and an opening 114 in the outboard end, or left end inFIGS. 5-8.

A hollow-closed cylinder 116 of a length less than the space between theends of the housing 110 has the cylinder rod 102 protruding out of theoutboard or left end thereof and has an opening 118 in the inboard orright end thereof, to a cylindrical cavity therein. A piston 120 isslidably mounted within the cavity of the cylinder 116 for reciprocalmovement therealong and has the piston rod 64 extending therefrom outthrough opening 118. The juncture between the piston rod 64 and thecylinder 116 is conventionally sealed to prevent the loss of fluidthrough opening 118. The cylinder 116 and piston 120 combination ismounted within the housing 110 by inserting the retracted cylinder 116and piston 120 therein and extending the piston rod 64 through theopening 112 and extending the cylinder rod 102 through opening 114. Asthe cylinder 116 is shorter in length than the distance between the endsof the housing 110, the cylinder 116 is free to reciprocate therebetweenwith the ends of the housing 110 limiting this movement.

The cylinder 116 has a circular groove therein around the cylinder rod102 for receiving a coil spring. A coil spring 122 is slid over thecylinder rod 102 with one end ofthe spring 122 seating against thecylinder 116 in the groove. The spring 122 is compressed and insertedinto the housing 110 with the cylinder 116. The compression is thenreleased allowing the other end of the spring 122 to seat against theinside of the outboard or left end of the housing 110 to bias thecylinder 116 against the inside of the inboard or right end of thehousing 110.

After the cylinder 116 and piston 120 have been mounted in the housing110, the piston rod 64 is hooked to the crank 60 and the cylinder rod102 is attached to link 98 by pivot pin 104 as previously described. Thedimensions of the cylinder 116 and piston 120 and cylinder and pistonrods 64 and 102 are such that when the flipper panel 34 is unlocked andopened, the cylinder and piston rods 102 and 64 are retracted with thecylinder 116 against the inboard or right end of the housing 116 andwhen the flipper panel 34 is lowered and locked, the cylinder and pistonrods are extended, with the cylinder 116 tightly compressing spring 122against the outboard or left end ofthe housing 110.

Each linear actuator 66 is powered by a reversible fluid pump 124 whichsupplies fluid through flexible tubes 126 ans 128 to passages 130 and132 through the walls of the cylinder 116. The passage 130 enters thecylindrical cavity at the outboard or left end and the passage 132enters the cylinder cavity at the inboard or right end for alternativelysupplying or exhausting fluid to either side of piston 120 to provide adifferential fluid pressure on the piston 120 and cylinder 116. Thefluid pump 124, the tubes 126 and 128, passages 130 and 132 and thecavity of cylinder 116 together form a closed fluid system supplied ondemand with fluid, from a conventional fluid reservoir system 134, shownschematically in FIG. 9.

Each pump 124 is driven by a reversible electric motor, incorporatedtherein, across a source of power such as battery and generator system136. As shown in FIG. 9, the battery and generator system 136 isconnected to a single-pole doublethrow switch 138 in an opening circuit140 and a closing circuit 142. Each circuit 140 and 142 has conventionalfluid pressure limit switches 144 in the respective tubes 126 and 128 tolimit the operation of the motor and pump 124. The switch 138 is mountedto the vehicle body so that it energizes circuit 140 as the respectivedoor is opened and energizes circuit 142 as the door 20 is closed.

When the closure is mounted over opening 14, the operation of theflipper panel 34 is automatic as far as the passenger is concerned. Asthe passenger opens the door 20, the switch 138 energizes the openingcircuit 140 to operate the fluid pump 124 in one direction. As shown inFIG. 5, when the fluid actuator is in the position corresponding toflipper panel 34 being closed and locked and maintained thereby trappedfluid within the cavity of cylinder 116, the operation of the fluid pump124 in the one direction releases the trapped fluid. The released fluidexhausts the cavity through opening 130 and tube 126 and allows thespring 122 to drive the cylinder 116 to the right or inboard of thevehicle body 10 from the position shown in FIG. 5 to the position shownin FIG. 6 against the inboard or right end of housing 110. The movementof the cylinder 116 and the cylinder rod 102 to the right, pulls on link98 pivoting L-shaped member 94 and sliding locking pin aft of thevehicle body 10 to the unlocked position, unlocking the flipper panel 34as previously described.

With the flipper panel 34 unlocked, continued operation of the fluidmotor 124 in the one direction supplies fluid through tube 128 andpassage 132 to the cavity on the right or inboard side of the piston todrive the piston 120 to the left or outboard of the vehicle from theposition shown in FIG. 6 to the position shown in FIG. 7. Movement ofthe piston 120 and the piston rod 64 to the left or outboard, rotatescrank 60, shaft 56, square tapered pin 38 and gear section 44 in onedirection to rotate gear section 52, hinge strap 48, and flipper panel34 in the opposite direction, raising the flipper panel 34 to openposition. When the flipper panel reaches the open position, the piston120 is limited from moving to the left any further so that the continuedsupplying of fluid in the one direction, by the fluid pump 124, raisesthe differential fluid pressure until the respective limit switch 144shuts ofl the pump 124. The flipper panel 34 is now fully opened forpassenger entry or exit and is maintained in the open position by thedifferential fluid pressure in the cylinder 116 against the right sideof piston 120.

As the passenger closes the door 20, the switch 138 energizes theclosing circuit 142 to operate the fluid pump in the opposite directionsupplying fluid through tube 126 and passage to the cylinder cavity onthe left or outboard side of piston 120. The fluid on the left side ofpiston 120 drives the fluid on the right side of piston 120 throughpassage 132 and tube 128 while moving the piston to the right or inboardfrom the position in FIG. 7 to the position in FIG. 8. The cylinder 116will not move to the left because of the spring 122. The movement of thepiston 120 and the piston rod 64 to the right or inboard, rotates crank60, shaft 56, square tapered pin 38 and gear section 44 in the oppositedirection to rotate gear section 52, hinge strap 48 and flipper panel 34in the one direction, lowering the flipper panel 34 to the closedposition. Notice in FIG. 8, that the flipper panel 34 has reached theclosed position and is limited from further downward movement by itsengagement with the windshield header 16, while the piston 120 still hastravel to the right remaining in the cylinder cavity.

With the flipper panel 34 closed, continued operation of the fluid pump124 in the opposite direction continues to supply fluid to the left sideof the piston 120 but the piston is restrained from moving to the rightby the flipper panel 34 engaging the windshield header 16 so that thefluid now moves the cylinder 116 to the left or outboard against thebiasing of spring 122 from the position shown in FIG. 8 to the positionshown in FIG. 5. The movement of the cylinder 116 and the cylinder rod102 to the left or outboard pushes link 98, pivoting bellcrank 94 andsliding locking pin 90 forward on the vehicle body 10 into cylindricalopening 76 driving rod 70 and bolt 72 under the windshield header 16 tolock the flipper panel 34 to the vehicle body as previously described.Once the cylinder 116 has completely compressed spring 122 against theend of the housing 110, it can move no further left or outboard so thatthe continued supply of fluid by the fluid pump 124 in the oppositedirection raises the differential fluid pressure until limit switch 144shuts off the fluid pump 124. The flipper panel 34 is now closed andlocked where it will be maintained by the differential fluid pressure inthe cylinder cavity acting against the left or outboard end of thepiston 120 until the door 20 is again opened to repeat the sequence.

The flipper panel 34 is maintained in either the open position or thelowered and locked position by differential fluid pressure within thecylindrical cavity. As a practical matter, this differential fluidpressure will drop as a result of fluid leakage over a period of time.However, with the respective limit switches 144 breaking an otherwiseclosed circuit in response to high fluid pressure, when the fluidpressure drops significantly, the limit switch 144 will close thecircuit to operate the fluid pump 124 in the correct direction torestore the pressure to the proper level. Thus the differential fluidpressure maintaining the flipper panel 34 in a terminal position, isautomatically kept sufficiently high by the limit switch 144.

To remove the flipper panel roof section completely, both doors must beopened. The opening of both doors 20, unlocks and opens both flipperpanels 34 as previously described. Once both flipper panels 34 areopened, the flipper panel roof section 30 is removed by unlatching toplatch 40 and lifting the flipper panel roof section 30 away aspreviously described.

in remounting the closure 30, both doors 21] must be opened and theflipper panels 34 also must be in the open position, to obtaincorrespondence between the positions of the square tapered holes 28 andthe square tapered pins 38. The closure 30 is remounted as previouslydescribed and the top latch 40 is latched before the doors 20 are closedto close the flipper panels 34.

In this embodiment, fluid pressure was used to move the piston andcylinder but fluid vacuum could be used as an alternative and in suchcase the tubes 126 and 128 would have to be reversed but the piston andcylinder would operate the same.

In this embodiment, the cylinder drove the locking mechanism and thepiston drop the flipper panel. However, by reversing the locations ofthe piston and cylinder and biasing the piston rather than the cylinder,the same sequential operation could be obtained.

It is also possible to add linkages to the raising mechanism and thelocking mechanism so that extending the piston and cylinder would unlockand raise the flipper panel and retracting the piston and cylinder wouldlower the flipper panel and lock it. In such case the cylinder wouldhave to be biases to the extended position for the actuator to have theproper sequence of movements.

It is also possible to obtain a sequential arcuate motion directly byusing a pivoted cylinder with an arcuate cylindrical cavity and a matingpiston with an arcuate piston rod.

Many other combinations of the above possibilities can obviously bedevised by a skilled artisan in light of this specification and suchcombinations are covered by the following claims.

Thus the removable closure for a vehicle body of this inventionpivotally mounts flipper panels driven between an open position openingthe vehicle body and a closed and locked position closing the vehiclebody by sequentially operating a linear actuator.

What is claimed is:

l. A removable closure for an opening in a vehicle body comprising, abase located transverse of the opening adjacent an edge thereof meansreleasably mounting the base to the vehicle body, a flipper panel, meanspivotally mounting the flipper panel to the base for pivotal movementrelative thereto between open and closed positions with respect to theopening, means for selectively releasing the base-mounting means toremove the base and the flipper panel as a unit and completely open theopening, actuator means mounted to the body, and means operablyconnecting the actuator means and the flipper panel to move the flipperpanel between open and closed positions, and means releasing theoperating means upon removal of the base and panel and reconnecting theoperating means upon remounting of the base and panel.

2. A removable closure for a vehicle body having a door mounted thereonfor opening and closing movement and an opening in the roof thereof,comprising, a base located adjacent an edge of the opening, selectivelyreleasable means securing the base to the body, a flipper panelpivotally mounted to the base for pivotal movement relative theretobetween a closed position closing the opening and an open position, overthe opening, driven means located on the base for moving the flipperpanel between open and closed positions, cooperating releasable lockingmeans on the flipper panel and the body for selectively locking theclosed flipper panel to the body, actuator means mounted on the body,first means operably connecting the actuator means to the locking means,second means operably releasably connecting the actuator means to thedriven means, and control means responsive to the movement of the doorfor controlling the actuator means, opening movement of the doorenergizing the control means to operate the actuator means tosequentially release the locking means through the first means andunlock the flipper panel, and to drive the driven means through thesecond means to move the closed flipper panel to the open position,closing movement of the door energizing the control means to operate theactuator means to sequentially drive the driven means through the secondmeans to move the open flipper panel to the closed position and tooperate the locking means through the first means to lock the closedflipper panel to the body, the base and the flipper panel being manuallyremovable when the panel is in the open position by selectivelyreleasing the base securing means, the second means being disconnectedfrom the driven means by the removal of the flipper panel and the base,and being reconnected by the remounting thereof.

3. A removable closure for a vehicle body having a door mounted thereonfor opening and closing movement and an opening in the roof thereof,comprising: a base located centrally across the opening and dividing theopening into two parts, selectively releasable means securing the baseto the roof, a pair of flipper panels, each flipper panel beingpivotally mounted to the base for pivotal movement relative theretobetween a closed position closing a respective one part of the openingand an open position opening a respective one part of the opening, thebase and the closed flipper panels together completely closing theopening, driven means for each flipper panel on the base for moving arespective flipper panel between open and closed positions, cooperatingreleasable locking means on each flipper panel and on the body forlocking the closed flipper panel to the body, actuator means for eachflipper panel mounted on the body, first means operably connecting theactuator means to a respective locking means, second means releasablyoperably connecting the actuator means to a respective driven means, andcontrol means for each panel responsive to movement of a respective doorfor controlling a respective actuator means, opening movement of thedoor energizing the control means to operate the actuator tosequentially release the respective locking means through the respectivefirst means and unlock the respective flipper panel and to drive therespective driven means through the respective second means to move theclosed respective flipper panel to the open position, closing movementof the door energizing the control means to operate the respectiveactuator to sequentially drive the respective driven means through therespective second means to move the open respective flipper panel to theclosed position and to operate the respective locking means through therespective first means to lock the closed respective flipper panel tothe body, the base and the flipper panels being manually removable whenthe flipper panels are both in the open position by selectivelyreleasing the securing means, both second means being disconnected fromboth driven means by the removal of the base and flipper panels and bothsecond means being reconnected to both driven means by the remountingthereof.

4. A removable closure for a vehicle body having a door mounted thereonfor opening and closing movement and an opening in the roof thereof,comprising, a base located adjacent an edge of the opening, selectivelyreleasable means securing the base to the roof, a flipper panelpivotally mounted to a respective side of the base for pivotal movementrelative to the base between a closed position and an open position withrespect to the opening, means on the base and on the roof engaged by theflipper panel for limiting the movement of the flipper panel, the meanson the roof limiting the movement of the flipper panel in the closedposition and the means on the base limiting the movement of the flipperpanel in the open position, driven means located on the base for movingthe flipper panel between open and closed positions, cooperatingreleasable locking means on the flipper panel and on the roof forlocking the closed flipper panel to the roof, an actuator mounted on thebody and having a movable cylinder element with a cavity therein, and amovable piston element mounted within the cavity of the cylinder, thepiston element and cylinder element being extendibly and retractablymovable relative to each other by differential fluid pressure, theclosed ends of the cylinder element limiting the travel of the pistonelement relative the cylinder element in either direction, first meansoperably connecting the one element to the locking means for the flipperpanel to move the respective locking means to the locked position uponmovement of the one element in the one direction relative to the otherelement and to move the locking means to the unlocked position uponmovement of the one element in the opposite direction relative to theother element, stop means limiting the movement of the one element inthe opposite direction when the locking means reaches the unlockedposition, means biasing the one element in the opposite direction,second means releasably operably connecting the other element to thedriven means for the flipper panel to move the flipper panel to the openposition upon movement of the other element in the one directionrelative to the one element and to move the flipper panel to the closedposition upon movement of the other element in the opposite directionrelative to the one element, the closure reaching the closed positionbefore the piston element reaches the end of the cylinder element in theopposite direction, means for the actuator to selectively providedifferential fluid pressure between the elements, and control means foreach panel responsive to movement of a door for controlling thedifferential fluid pressure means, opening movement of the doorenergizing the control means to provide the difierential fluid pressurebetween the elements when the flipper panel is in the closed and thelocking means is in the locking position cooperating with the biasingmeans to move the one element in the opposite direction and move thelocking means through the first means to the unlocked position, the stopmeans limiting the movement of the one element in the oppositedirection, and then to move the other element in the one direction tomove the flipper panel through the second means to the open position,the movement of the other element in the one direction being limited bythe flipper panel engaging the means on the base, closing movement ofthe door energizing the control means to provide the differential fluidpressure means to provide a difierential fluid pressure between theelements when the flipper panel is in the open position and the lockingmeans is in the unlocked position moving the other element in theopposite direction to move the flipper panel through the second means tothe closed position, the flipper panel engaging the means on the roof tolimit the movement of the other element in the opposite direction andthen moving the one element in the one direction against the action ofthe biasing means to move the locking means through the first means tothe locked position to lock the closed flipper panel to the body, thebase and flipper panel being manually removable when the flipper panelis in the open position by selectively releasing the securing means, thedriven means being disconnected from the second means by the removal ofthe base and the flipper panel and being reconnected to the second meansby the remounting thereof.

5. In a vehicle body having a closure mounted thereon for swingingmovement between open and closed positions and locking means movablebetween locked and unlocked positions, for the closure and the body, thecombination comprising, a linear actuator having a movable cylinderelement and a movable piston element within the cylinder element, eachelement being movable relative to the other by differential fluidpressure, means connecting one element to the closure to move theclosure to the open position upon movement of the one element in onedirection relative to the other element, means connecting the otherelement to the locking means to move the locking means to the unlockedposition upon movement of the other element in the opposite direction,means biasing the other element in the opposite direction, means forselectively providing a differential fluid pressure between theelements, differential fluid pressure between the elements when theclosure is in the closed position and the locking means is in the lockedposition cooperating with the biasing means to move the other element inthe opposite direction and move the locking means to the unlockedposition, first stop means limiting the movement of the other element inthe opposite direction when the locking means is in the unlockedposition, differential fluid pressure between the elements when theclosure is in the closed position and the locking means is in theunlocked position cooperating with the first stop means to move the oneelement in the one direction to move the closure to the open position,and second stop means limiting the movement of the one element in theone direction when the closure is in the open position.

6. In a vehicle body having a closure mounted thereon for swingingmovement between open and closed positions and locking means for theclosure and the body movable between locked and unlocked positions, thecombination comprising, a linear actuator having a movable cylinderelement and a movable piston element within the cylinder element, eachelement being movable relative to the other by differential fluidpressure, means connecting one element to the closure to move theclosure to the closed position upon movement of the one element in onedirection relative to the other element, means connecting the otherelement to the locking means to move the locking means to the lockedposition upon movement of the other element in the opposite direction,means biasing the other element in the one direction, means forselectively providing a differential fluid pressure between the elementswhen the closure is in the open position and the locking means is in theunlocked position first moving the one element in the one direction tomove the closure to the closed position, first stop means limiting themovement of the one element in the one direction when the closure is inthe closed position, and moving the other element against the action ofthe biasing means in the opposite direction to move the locking means tothe locked position, and second stop means limiting the movement of theother element in the opposite direction when the locking means is in thelocked position.

7. In a vehicle body having a closure mounted thereon for swingingmovement between open and closed positions and locking means for theclosure and the body movable between locked and unlocked positions, thecombination comprising, a linear actuator having a movable cylinderelement and a movable piston element within the cylinder element, eachelement being extendable and retractable relative to the other bydifferential fluid pressure, means connecting one element to the closureto move the closure to the open position upon retraction of the oneelement in one direction relative to the other element and to move theclosure to the closed position upon extension of the one element in theopposite direction relative to the other element, means connecting theother element to the locking means to move the locking means to thelocked position upon extension of the other element in the one directionand to move the the locking means to the unlocked position uponretraction of the other element in the opposite direction, means biasingthe other element in the opposite direction, means for selectivelyproviding differential fluid pressure between the elements, differentialfluid pressure between the elements when the closure is in the closedposition and the locking means is in the locked position cooperatingwith the biasing means to retract the other element in the oppositedirection to move the locking means to the unlocked position, first stopmeans limiting the movement of the other element in the oppositedirection when the locking means is in the unlocked position,differential fluid pressure between the elements when the closure is inthe closed position and locking means is in the unlocked positioncooperating to retract the one element in the one direction to move theclosure to the open position, second stop means limiting the movement ofiii the one element in the one direction when the closure is in the openposition, differential fluid pressure between the elements when theclosure is in the open position and the locking means is in the unlockedposition extending the one element in the opposite direction to move theclosure to the closed position. third stop means limiting the movementof the one element in the opposite direction when the closure is in theclosed position, differential fluid pressure between the elements whenthe closure is in the closed position and the locking means is in theunlocked position extending the other element against the action of thebiasing means in the one direction to move the locking means to thelocked position and fourth stop means limiting the movement of the otherelement in the one direction when the locking means is in the lockedposition.

8. in a vehicle body having a closure mounted thereon for swingingmovement between open and closed positions and locking means for theclosure and the body movable between locked and unlocked positions, thecombination comprising, a linear actuator having a movable closedcylinder element and a movable piston element within the cylinderelement, each element being extendible and retractable relative to theother by differential fluid pressure with the closed ends of thecylinder element providing stop means limiting the travel of the pistonelement relative to the cylinder element in either direction, stop meanslimiting the movement of the cylinder element relative to the pistonelement in either direction, first means connecting one element to theclosure to move the closure to the open position upon retraction of theone element in the one direction relative to the other element and tomove the closure to the closed position upon extension of the oneelement in the opposite direction relative to the other element, theclosure reaching the closed position before the stop means limits themovement of the one element in the opposite direction, second meansconnecting the other element to the locking means to move the lockingmeans to the locked position upon extension of the other element in theone direction and to move the locking means to the unlocked positionupon retraction of the other element in the opposite direction, thelocking means being unlocked when the stop means limits the movement ofthe other element in the opposite direction and being locked when thestop means limits the movement of the other element in the onedirection, means biasing the other element in the opposite direction,means for selectively providing a differential fluid pressure betweenthe elements, differential fluid pressure between the elements when theclosure is in the closed position and the locking means is in the lockedposition cooperating with the biasing means to retract the other elementin the opposite direction to move the locking means to the unlockedposition, the stop means limiting the movement of the other element inthe opposite direction, difierential fluid pressure between the elementswhen the closure is in the closed position and locking means is in theunlocked position cooperating to retract the one element in the onedirection to move the closure to the open position, stop means limitingthe movement of the one element in the one direction, ditferential fluidpressure between the elements when the closure is in the open positionand the locking means is in the unlocked position extending the oneelement in the opposite direction to move the closure to the closedposition, the stop means limiting the movement of the one element in theopposite direction, and differential fluid pressure between the elementswhen the closure is in the closed position and the locking means is inthe unlocked position extending the other element in the one directionagainst the action of the biasing means to move the locking means to thelocked position, the stop means limiting the movement of the otherelement in the one direction.

1. A removable closure for an opening in a vehicle body comprising, a base located transverse of the opening adjacent an edge thereof, means releasably mounting the base to the vehicle body, a flipper panel, means pivotally mounting the flipper panel to the base for pivotal movement relative thereto between open and closed positions with respect to the opening, means for selectively releasing the base-mounting means to remove the base and the flipper panel as a unit and completely open the opening, actuator means mounted to the body, and means operably connecting the actuator means and the flipper panel to move the flipper panel between open and closed positions, and means releasing the operating means upon removal of the base and panel and reconnecting the operating means upon remounting of the base and panel.
 2. A removable closure for a vehicle body having a door mounted thereon for opening and closing movement and an opening in the roof thereof, comprising, a base located adjacent an edge of the opening, selectively releasable means securing the base to the body, a flipper panel pivotally mounted to the base for pivotal movement relative thereto between a closed position closing the opening and an open position, over the opening, driven means located on the base for moving the flipper panel between open and closed positions, cooperating releasable locking means on the flipper panel and the body for selectively locking the closed flipper panel to the body, actuator means mounted on the body, first means operably connecting the actuator means to the locking means, second means operably releasably connecting the actuator means to the driven means, and control means responsive to the movement of the door for controlling the actuator means, opening movement of the door energizing the control means to operate the actuator means to sequentially release the locking means through the first means and unlock the flipper panel, and to drive the driven means through the second means to move the closed flipper panel to the open position, closing movement of the door energizing the control means to operate the actuator means to sequentially drive the driven means through the second means to move the open flipper panel to the closed position and to operate the locking means through the first means to lock the closed flipper panel to the body, the base and the flipper panel being manually removable when the panel is in the open position by selectively releasing the base securing means, the second means being disconnected from the driven means by the removal of the flipper panel and the base, and being reconnected by the remounting thereof.
 3. A removable closure for a vehicle body having a door mounted thereon for opening and closing movement and an opening in the roof thereof, comprising: a base located centrally across the opening and dividing the opening into two parts, selectively releasable means securing the base to the roof, a pair of flipper panels, each flipper panel being pivotally mounted to the base for pivotal movement relative thereto between a closed position closing a respective one part of the opening and an open position opening a respective one part of the opening, the base and the closed flipper panels together completely closing the opening, driven means for each flipper panel on the base for moving a respective flipper panel between open and closed positions, cooperating releasable locking means on each flipper panel and on the body for locking the closed flipper panel to the body, actuator means for each flipper panel mounted on the body, first means operably connecting the actuator means to a respective locking means, second means releasably operably connecting the actuator means to a respective driven means, and control means for each panel responsive to movement of a respective door for controlling a respective actuator means, opening movement of the door energizing the control means to operate the actuator to sequentially release the respective locking means through the respective first means and unlock the respective flipper panel and to drive the respective driven means through the respective second means to move the closed respective flipper panel to the open position, closing movement of the door energizing the control means to operate the respective actuator to sequentially drive the respective driven means through the respective second means to move the open respective flipper panel to the closed position and to operate the respective locking means through the respective first means to lock the closed respective flipper panel to the body, the base and the flipper panels being manually removable when the flipper panels are both in the open position by selectively releasing the securing means, both second means being disconnected from both driven means by the removal of the base and flipper panels and both second means being reconnected to both driven means by the remounting thereof.
 4. A removable closure for a vehicle body having a door mounted thereon for opening and closing movement and an opening in the roof thereof, comprising, a base located adjacent an edge of the opening, selectively releasable means securing the base to the roof, a flipper panel pivotally mounted to a respective side of the base for pivotal movement relative to the base between a closed position and an open position with respect to the opening, means on the base and on the roof engaged by the flipper panel for limiting the movement of the flipper panel, the means on the roof limiting the movement of the flipper panel in the closed position and the means on the base limiting the movement of the flipper panel in the open position, driven means located on the base for moving the flipper panel between open and closed posItions, cooperating releasable locking means on the flipper panel and on the roof for locking the closed flipper panel to the roof, an actuator mounted on the body and having a movable cylinder element with a cavity therein, and a movable piston element mounted within the cavity of the cylinder, the piston element and cylinder element being extendibly and retractably movable relative to each other by differential fluid pressure, the closed ends of the cylinder element limiting the travel of the piston element relative the cylinder element in either direction, first means operably connecting the one element to the locking means for the flipper panel to move the respective locking means to the locked position upon movement of the one element in the one direction relative to the other element and to move the locking means to the unlocked position upon movement of the one element in the opposite direction relative to the other element, stop means limiting the movement of the one element in the opposite direction when the locking means reaches the unlocked position, means biasing the one element in the opposite direction, second means releasably operably connecting the other element to the driven means for the flipper panel to move the flipper panel to the open position upon movement of the other element in the one direction relative to the one element and to move the flipper panel to the closed position upon movement of the other element in the opposite direction relative to the one element, the closure reaching the closed position before the piston element reaches the end of the cylinder element in the opposite direction, means for the actuator to selectively provide differential fluid pressure between the elements, and control means for each panel responsive to movement of a door for controlling the differential fluid pressure means, opening movement of the door energizing the control means to provide the differential fluid pressure between the elements when the flipper panel is in the closed and the locking means is in the locking position cooperating with the biasing means to move the one element in the opposite direction and move the locking means through the first means to the unlocked position, the stop means limiting the movement of the one element in the opposite direction, and then to move the other element in the one direction to move the flipper panel through the second means to the open position, the movement of the other element in the one direction being limited by the flipper panel engaging the means on the base, closing movement of the door energizing the control means to provide the differential fluid pressure means to provide a differential fluid pressure between the elements when the flipper panel is in the open position and the locking means is in the unlocked position moving the other element in the opposite direction to move the flipper panel through the second means to the closed position, the flipper panel engaging the means on the roof to limit the movement of the other element in the opposite direction and then moving the one element in the one direction against the action of the biasing means to move the locking means through the first means to the locked position to lock the closed flipper panel to the body, the base and flipper panel being manually removable when the flipper panel is in the open position by selectively releasing the securing means, the driven means being disconnected from the second means by the removal of the base and the flipper panel and being reconnected to the second means by the remounting thereof.
 5. In a vehicle body having a closure mounted thereon for swinging movement between open and closed positions and locking means movable between locked and unlocked positions, for the closure and the body, the combination comprising, a linear actuator having a movable cylinder element and a movable piston element within the cylinder element, each element being movable relative to the other by differential fluid pressure, means connecting one element to the closure to move the closure to the open position upon movement of the one element in one direction relative to the other element, means connecting the other element to the locking means to move the locking means to the unlocked position upon movement of the other element in the opposite direction, means biasing the other element in the opposite direction, means for selectively providing a differential fluid pressure between the elements, differential fluid pressure between the elements when the closure is in the closed position and the locking means is in the locked position cooperating with the biasing means to move the other element in the opposite direction and move the locking means to the unlocked position, first stop means limiting the movement of the other element in the opposite direction when the locking means is in the unlocked position, differential fluid pressure between the elements when the closure is in the closed position and the locking means is in the unlocked position cooperating with the first stop means to move the one element in the one direction to move the closure to the open position, and second stop means limiting the movement of the one element in the one direction when the closure is in the open position.
 6. In a vehicle body having a closure mounted thereon for swinging movement between open and closed positions and locking means for the closure and the body movable between locked and unlocked positions, the combination comprising, a linear actuator having a movable cylinder element and a movable piston element within the cylinder element, each element being movable relative to the other by differential fluid pressure, means connecting one element to the closure to move the closure to the closed position upon movement of the one element in one direction relative to the other element, means connecting the other element to the locking means to move the locking means to the locked position upon movement of the other element in the opposite direction, means biasing the other element in the one direction, means for selectively providing a differential fluid pressure between the elements when the closure is in the open position and the locking means is in the unlocked position first moving the one element in the one direction to move the closure to the closed position, first stop means limiting the movement of the one element in the one direction when the closure is in the closed position, and moving the other element against the action of the biasing means in the opposite direction to move the locking means to the locked position, and second stop means limiting the movement of the other element in the opposite direction when the locking means is in the locked position.
 7. In a vehicle body having a closure mounted thereon for swinging movement between open and closed positions and locking means for the closure and the body movable between locked and unlocked positions, the combination comprising, a linear actuator having a movable cylinder element and a movable piston element within the cylinder element, each element being extendible and retractable relative to the other by differential fluid pressure, means connecting one element to the closure to move the closure to the open position upon retraction of the one element in one direction relative to the other element and to move the closure to the closed position upon extension of the one element in the opposite direction relative to the other element, means connecting the other element to the locking means to move the locking means to the locked position upon extension of the other element in the one direction and to move the the locking means to the unlocked position upon retraction of the other element in the opposite direction, means biasing the other element in the opposite direction, means for selectively providing differential fluid pressure between the elements, differential fluid pressure between the elements when the closure is in the closed position and the locking Means is in the locked position cooperating with the biasing means to retract the other element in the opposite direction to move the locking means to the unlocked position, first stop means limiting the movement of the other element in the opposite direction when the locking means is in the unlocked position, differential fluid pressure between the elements when the closure is in the closed position and locking means is in the unlocked position cooperating to retract the one element in the one direction to move the closure to the open position, second stop means limiting the movement of the one element in the one direction when the closure is in the open position, differential fluid pressure between the elements when the closure is in the open position and the locking means is in the unlocked position extending the one element in the opposite direction to move the closure to the closed position, third stop means limiting the movement of the one element in the opposite direction when the closure is in the closed position, differential fluid pressure between the elements when the closure is in the closed position and the locking means is in the unlocked position extending the other element against the action of the biasing means in the one direction to move the locking means to the locked position and fourth stop means limiting the movement of the other element in the one direction when the locking means is in the locked position.
 8. In a vehicle body having a closure mounted thereon for swinging movement between open and closed positions and locking means for the closure and the body movable between locked and unlocked positions, the combination comprising, a linear actuator having a movable closed cylinder element and a movable piston element within the cylinder element, each element being extendible and retractable relative to the other by differential fluid pressure with the closed ends of the cylinder element providing stop means limiting the travel of the piston element relative to the cylinder element in either direction, stop means limiting the movement of the cylinder element relative to the piston element in either direction, first means connecting one element to the closure to move the closure to the open position upon retraction of the one element in the one direction relative to the other element and to move the closure to the closed position upon extension of the one element in the opposite direction relative to the other element, the closure reaching the closed position before the stop means limits the movement of the one element in the opposite direction, second means connecting the other element to the locking means to move the locking means to the locked position upon extension of the other element in the one direction and to move the locking means to the unlocked position upon retraction of the other element in the opposite direction, the locking means being unlocked when the stop means limits the movement of the other element in the opposite direction and being locked when the stop means limits the movement of the other element in the one direction, means biasing the other element in the opposite direction, means for selectively providing a differential fluid pressure between the elements, differential fluid pressure between the elements when the closure is in the closed position and the locking means is in the locked position cooperating with the biasing means to retract the other element in the opposite direction to move the locking means to the unlocked position, the stop means limiting the movement of the other element in the opposite direction, differential fluid pressure between the elements when the closure is in the closed position and locking means is in the unlocked position cooperating to retract the one element in the one direction to move the closure to the open position, stop means limiting the movement of the one element in the one direction, differential fluid pressure between the elements when the closure is in the open position and the locking means is in the unlocked position extending the one element in the opposite direction to move the closure to the closed position, the stop means limiting the movement of the one element in the opposite direction, and differential fluid pressure between the elements when the closure is in the closed position and the locking means is in the unlocked position extending the other element in the one direction against the action of the biasing means to move the locking means to the locked position, the stop means limiting the movement of the other element in the one direction. 